gd: imagecreatefrom how to check

[avlee]

Hello

I have some dynamically generated images in files.
I need to open them using:
imagecreatefrom png
imagecreatefrom jpeg

i need to check if the file is png or jpeg.

How can i do it ?

Thanx

[Toby A Inkster]

Re: gd: imagecreatefrom how to check

avlee wrote:

i need to check if the file is png or jpeg.
How can i do it ?

Open the file using fopen() and read in the first 10 bytes. Now close the
file. Match the first ten bytes using the following:

$is_image_png = preg_match('/^.PNG/', $ten_bytes);
$is_image_jpeg = preg_match('/(Exif|JFIF)$/', $ten_bytes);

Note, it's also fairly easy to check for a few other common file types:

$is_image_gif = preg_match('/^GIF8[79]/', $ten_bytes);
$is_audio_ogg = preg_match('/^Ogg/', $ten_bytes);
$is_script = preg_match('/^#!\//', $ten_bytes);

Of course, it's not a rigid test that the file really is of that type, but
it's a nice quick check, and should help you differentiate between JPEG
and PNG images fairly easily.

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